fix: add nginx security headers (server_tokens off, Content-Type on /health)

Author: shahboura

nginx.conf

@@ -4,8 +4,11 @@ server {
     root /usr/share/nginx/html;
     index index.html;
 
+    server_tokens off;
+
     location /health {
         access_log off;
+        add_header Content-Type text/plain;
         return 200 "ok";
     }